(i) Technical Field
The present invention relates to focal plane shutters and optical apparatus.
(ii) Related Art
For example, Japanese Patent Unexamined Application Publication No. 2010-34818 discloses an image pickup device with an electronic leading blade and mechanical leading blades. After the electronic leading blade moves in the state where the trailing blades recede from an opening of a board, the trailing blades close the opening to perform exposure.
After the exposure operation is finished, a reading operation of image data from the image pickup element is performed. During the reading operation of image data, shading of light entering the image pickup element is required taking image quality into consideration. Therefore, after the exposure operation is finished, maintaining the state where the trailing blades close the opening for a predetermined period is required.
In case of a normally-open type shutter, after the exposure operation is finished, the trailing blade recedes from the opening after the reading operation of image data from the image pickup element is performed. This enables a live view display to display outputs from the image pickup element on a liquid crystal monitor of a camera in real time.
Also, in case of continuous shooting, the trailing blades have to recede from the opening to perform a charging operation for the next shooting, after the reading operation of image data from the image pickup element is finished after the exposure operation is finished.
Therefore, after the exposure operation is finished, the trailing blade will not be driven until the reading operation of image data from the image pickup element is performed. Therefore, a shooting interval might not be shortened.